The ornamental design for a frontportion of a collar, as shown and described.
FIG. 1 is a perspective view of a front portion of a collar, showing my new design, in an environment of use;
FIG. 2 is a front elevation view thereof;
FIG. 3 is another front elevation view thereof;
FIG. 4 is a left elevation view thereof;
FIG. 5 is a right elevation view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is another perspective view thereof; showing my new design in an alternate environment of use.
The broken lines shown in the drawings illustrate portions of the front portion of a collar that form no part of the claimed design. The other broken lines illustrate environmental subject matter only and form no part of the claimed design.